Fast heart rate: Tachycardia means fast heart beat. Sinus node is the structure where normally heart rhythm and beat is originated, and it naturally responds to stimuli when the heart needs to beat faster. Inappropriate sinus tachycardia is when the heart is beating fast, when it shouldn't. ...Read more.
The atom is the smallest subdivision of an element which still retains the properties of that element. In fact, a very good definition of an atom is: the smallest part of an element that can enter into a chemical combination. There are around 118 elements known to man, of which 20-30 are really, really important.he parallel definition (to the element one above) for the molecule is: the smallest part of a compound that can enter into a chemical combination. Another definition, equally good, is that a molecule is the smallest stable part of a compound. Water is a typical example of a compound.
The smallest kind of molecule is composed of only two other atoms. The atoms can be of the same kind or of different kinds. Molecules that are composed of two atoms of the same kind are also referred to as elements. All molecules that have only two atoms are called diatomic molecules.f the molecule contains more than one kind of atom, it is called heteroatomic. The presence of homoatomic molecules indicates that not all elements prefer to be in the state of individual atoms. There are elements that are molecular and composed of two, four, or even eight atoms.